Nanostructured Tin Oxide Gas Diffusion Electrode Fabrication for Carbon Dioxide Electroreduction in Sustainable Energy Systems

The accumulation of atmospheric CO₂ from fossil fuels presents critical environmental challenges. Electrochemical CO₂ reduction (CO₂RR) can convert CO₂ into valuable chemicals but is limited by conventional electrodes using polymer binders and solvents that hinder efficiency. This research develops a binder-free nanostructured tin oxide gas diffusion electrode (SnO₂-GDE) using a simple, scalable electrodeposition method. SnO₂ was deposited at 2-3 V from a tin chloride (SnCl₂.2H₂O) solution in ethanol-deionized water stabilized with hydrochloric acid (HCl), followed by thermal treatment at 200°C for 1 hour. X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) confirmed a tetragonal SnO₂ structure with uniform nanostructure morphology. Electrochemical tests in an H-cell showed that the 2.5 V sample had the lowest charge transfer resistance (Rct) and a reduction peak at -0.68 V, indicating high catalytic activity. Tafel analysis confirmed faster charge transfer kinetics. This eco-friendly, binder-free electrode method offers scalable potential for CO₂-to-formic acid, and supporting the development of green electrochemical systems for carbon-neutral energy production.